During semiconductor wafer manufacture, dielectric films (e.g., UV sensitive amorphous composite or oxides) are deposited on the wafer surface. The dielectric films are cured using ultraviolet (UV) light. In more recent processes, high energy UV (e.g., ultraviolet excimer lamps) are used to enhance the curing speed.
The UV light is passed from the light source through a transmission window, and into the curing chamber, where the light makes contact with the dielectric film. Generally, the transmission window is held in place within the UV chamber between two plates. In addition, an O-ring is placed between the junction of each plate and the adjacent face of the transmission window. The O-ring prevents out-gassing/leakage of the gasses produced during the curing process from the plate-window junction, and further prevents leakage of air into the chamber.
But due to the high heat and light intensity generated from the UV lamp, particularly with the more modern high energy UV lights, such O-ring seals break down quickly. Damaged seals risks out-gassing, particle generation, and leakage around the transmission window. Moreover, faster breakdown means frequent downtime for maintenance of the curing chambers to replace the O-rings, with attendant cost and lost productivity. Accordingly, there is a need in the art to better protect O-rings from UV radiation.